The best viewing location will be Indonesia. The next best? Australia, along with other parts of Asia and Eastern Europe.

Astronomers said it will be visible in Australia, with a little help from a telescope, from around 0624 AEDT on February 16.

"What you would see through a small telescope would be something like a star, a small point of light... that moved against a background of stars," said Tim Spahr, of the Harvard-Smithsonian's Minor Planet Centre.

NASA scientists said there is no reason to worry. They insist there is absolutely no chance of a collision next Friday.

"This asteroid's orbit is so well known that we can say with confidence that even considering it's orbital uncertainties, it can pass no closer than 27,500km from the Earth's surface.

"At the same time, it will pass 5,000 miles (8000km) inside the ring" of satellites, Yeomans told reporters, saying the asteroid's path puts it right in the "sweet spot" to avoid having any damaging impact.

But if the asteroid -which was only discovered by a Spanish dentist in February last year - did ever hit Earth in the distant future, it is estimated that it would produce a blast the equivalent of 2.5 megatons of TNT - - enough to flatten a large area but not globally catastrophic.

The atomic bomb which destroyed Hiroshima was equivalent to 12,500 tons.

The last asteroid of similar size to hit Earth was in Tunguska Siberia in 1908 and wasestimated at 3−20 megatons.

That spacerock flattened trees for miles.

The asteroid measures about 45m in diameter. That makes it relatively small by celestial standards.

"The object that ... took out the dinosaurs was about 10 kilometres," said Yeomans.

Asteroids about 50m in diameter are expected to impact Earth once every 1200 years or so.

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